The transformation of living cells by propelling microprojectiles at those cells at high velocity, with the microprojectiles carrying exogenous DNA or RNA, was originally proposed by T. Klein, E. Wolf, R. Wu and J. Sanford, Nature 327, 70 (1987). See also J. Sanford et al., Particulate Science and Technology 5, 27 (1987). The original work involved the tranformation of onion epidermal cells with RNA derived from tobacco mosaic virus. The findings with onion epidermal cells have been extended to other plants. For example, the transformation of soybean callus by particle bombardment is described by P. Christou et al., Plant Physiol. 87, 671 (1988), and the transformation of soybean meristem is described by D. McCabe et al., Bio/Technology 6, 923 (1988). European Patent Application Publication No. 0 301 749 to P. Christou et al. The transformation of embryonic maize callus cells by particle bombardment is described by T. Klein et al., Proc. Natl. Acad. Sci. USA 85, 4305 (1988), and the production of transformed maize seed by the particle bombardment of maize pollen is described in European Patent Application Publication No. 0 270 357 to D. McCabe et al.
In addition to the transformation of plants, microprojectile bombardment has been used to transform cellular organelles. Mitochondrial transformation in yeast by particle bombardment is described by S. Johnston et al., Science 240, 1538 (1988), and chloroplast transformation in Chlamydomonas by particle bombardment is described by J. Boynton et al., Science 240, 1534 (1988).
The use of particle bombardment for the transformation of animal tissue or cells has received comparatively little attention. Sanford et al., Particulate Science and Technology 5, 27, 35-36 (1987), suggest the use of particle bombardment for human gene therapy, but do not suggest the tissue type or the developmental stage of tissue useful for carrying out such therapy. U.S. patent application Ser. No. 06/877,619, titled "Method for Transporting Substances Into Living Cells and Tissues and Apparatus Therefor," concerns the introduction of biological materials into cells by microprojectile bombardment. Suggested biological substances are stains such as fluorescent or radiolabled probes, viruses, organelles, vesicles, proteins such as enzymes or hormones, and nucleic acids such as DNA and RNA. Suggested procedures include: (a) the particle bombardment of animal cells such as eggs, bone marrow cells, muscle cells, and epiderman cells at page 16, lines 5-6; (b) the particle bombardment of human tissue or other animal tissue such as epidermal tissue, organ tissue, and tumor tissue at page 16, lines 13-14; and (c) human gene therapy for sickle cell anemia by the particle-mediated transformation of bone marrow tissue at page 22, lines 8-9.
W. Brill, Particle Propulsion by Electric Discharge (Tape of Speech at AAAS meeting on Plant Molecular Biology/Genetic Engineering for Agriculture (VI) (January 1989), discusses the transformation of nematodes to correct a missing body wall myosin gene by particle bombardment. The utility of transforming nematodes is, however, comparatively limited.
In view of the foregoing, an object of this invention is to provide new uses for the treatment of animals, particularly vertebrates, and their tissues and cells, by microprojectile bombardment.
A more particular object of this invention is to use microprojectile bombardment as a means for administering proteins or peptides to an animal subject.